Yamabond

[shadowjack1]

Heard a wench talking about using Yamabond for an engine rebuild. Anyone out there ever use it or know of anyone who has. He stated that it works better then what Porsche uses.

[88911coupe]

Theres a GREAT thread on sealants in the rebuild forum that talks about this as well as several others. I did not know about this till I was well into my rebuild but I might have used it if I had. It seems a bit hard to find, at least back when I first looked into it.

[Tippy]

I used Yamabond on my rebuild. Seemed to seal the engine cases fine but the cam towers leak a little. That might be my fault as I didn't resurface them.

This stuff is very watery and not comforting. I'd use a thicker sealant next time for extra insurance.

[smakuch]

I've found that Permatex MotoSeal works very well on Harley Engine cases. It's also gasoline resistant.
steve

[wachuko]

I don't get it, why not stick with the factory stuff??? Loctite 574

[kodioneill]

John Walker uses a product called Dirko I tried it on a rebuild and it seemed to work great. Stays flexible and no leaks from the towers or case halves.

[boyt911sc]

Originally Posted by shadowjack1

Heard a wench talking about using Yamabond for an engine rebuild. Anyone out there ever use it or know of anyone who has. He stated that it works better then what Porsche uses.

shadowjack,

Threebond 1194 is commonly used by 911 engine rebuilders as sealant for the crankcase perimeter (see 'Ultimate sealant thread') and Yamabond has the same material. Do a search and you'll find some other brand names using the same material.



Tony

[Tippy]

I don't get it, why not stick with the factory stuff??? Loctite 574

Have you ever seen a Japanese motorcycle/ATV leak oil? I haven't.

[Tippy]

From what I've read, Threebond is the maker of Yamabond, Hondabond, etc.

[wachuko]

Originally Posted by Tippy

Have you ever seen a Japanese motorcycle/ATV leak oil? I haven't.

Hahahahahaaha...good point. When I did the rebuild on the 951 I got both the Yamabond and the 574... when the time came I stuck with what Porsche uses... but this was some 12 years ago, not that much feedback available online at the time

[Tippy]

Yeah, I followed Henry Schmidt's advise since they've rebuilt 100's of 911 engines.

[shadowjack1]

Thanks guys.

[Walt Fricke]

Tippy

For the head to cam carrier sealing, nothing needs resurfacing. There is nothing to wear there - and even the small scratches you can create when trying to clean off old sealant ought easily to be resealed with new sealant.

One good thing about the 574 is that it appears that a new coat will soften/disolve a thin old coat. This approach has worked fine for me. However, I don't suppose the XXXBonds will do this, either on themselves and certainly not likely for other sealant types. So cleaning off the old sealant might be more important if switching.

As for leaks, I don't think any of my home rebuilt motors have leaked from the case flange joints, or from the head to cam carrier joints. Leaks seem to come from gasketed areas, or from the seals, either via the ID or the OD. And certainly from the rocker shafts, although usually those are more weeps which collect dirt than leaks which drip.